Method for producing color filter

ABSTRACT

A method for producing a color filter involves (A) forming a photosensitive coating film on a transparent electrically conductive layer provided on an outermost surface of a substrate having an alignment film, and exposing the photosensitive coating film to light in a first irradiation amount through a mask having a predetermined pattern of a certain light transmittance and at least once displacing the mask to another position on the photosensitive coating film and exposing the photosensitive coating film to light in a second irradiation amount different from the first irradiation amount through the mask; (B) developing and removing a photosensitive coating film portion exposed to light in one of smallest and largest irradiation amounts for exposing the transparent electrically conductive layer and electrodepositing a colored coating on the exposed electrically conductive layer for forming a colored layer thereon, operation of developing and removing the photosensitive coating film and electrodepositing the colored coating being repeated in sequence of difference in irradiation amounts to form different colored layers, respectively; and (A) transcribing the colored layers, the transparent electrically conductive layer and the alignment film onto another substrate.

BACKGROUND OF THE INVENTION

This invention relates to a method for producing a color filter and moreparticularly to a color filter advantageously employed as a color liquidcrystal display device.

Among the currently employed methods for preparing a color filter, thereare a dyeing method consisting in dyeing a transparent substrate with abinder containing dyes and pigments, a printing method and a pigmentdispersion method.

Since the dyeing method consists in selectively forming a thin resinfilm on a substrate with dyes, a resist printing process and aphotolithographic process need to be performed each time the color ischanged. Although resist printing is unnecessary with the printingmethod, there is a limit to the refinement of color patterns and, thelarger is the number of colors, the printing position becomes the worse.Although the fine color pattern is possible with the pigment dispersionmethod, a high precision photolithographic process needs to be performedeach time the color is changed, resulting in a complicated process.

For overcoming the deficiency, there is proposed in Japanese Laid-openPatent Application No. 59-114572 (1984) a method for producing a colorfilter by an electrodeposition coating method. With this method, atransparent electrode is prepared by patterning a transparentelectrically conductive film deposited on the substrate, and electricalvoltage is applied only to a portion of the patterned transparentelectrode which is to be dyed in the same color. The substrate isimmersed in a colored electrodeposition bath for forming a colored layerby electrodeposition. Electric voltage is then applied only to a portionof the substrate which is to be dyed in a different color, and thesubstrate is then immersed in a colored electrodeposition bath forforming a different color layer by electrodeposition. However, it isnecessary with this method to perform a high precision patterning of thetransparent electrode, and to pay meticulous care during the subsequentprocess not to break the fine pattern, because otherwise the subsequentcoloring process is rendered difficult. Besides, the patternedtransparent electrode needs to be electrically continuous, even in finepattern sections, so that limitations are imposed on the degree offreedom of the pattern shape.

In Japanese Laid-open Patent Application No. 63-210901 (1988), there isproposed a method consisting in forming colored layers by lightexposure, development and electrodeposition, using a mask havingpatterns only in areas to be dyed in the same colors and a positive typephotosensitive resin composition, and repeating the steps of lightexposure, development and electrodeposition a desired number of times.This method is inferior in stability because it makes use of a compoundcontaining unstable quinone diazido groups. Besides, if the quinonediazido compound is brought into contact with an aqueous alkalisolution, the quinone diazido compound in the unexposed part is alsoreacted with an aqueous alkali solution so that photosensitivity ismarkedly changed to present difficulties in the subsequent lightexposure and development steps.

In these electrodeposition methods a transparent electrode for formationof colored layers is simultaneously used as an electrode for driving aliquid crystal. However, since the colored layers formed on thetransparent electrode are made of an insulating material, the liquidcrystal driving voltage becomes exceedingly high. For this reason, atransparent electrode for driving the liquid crystal is additionallyprovided on the colored layers formed in accordance with the abovemethod for lowering the driving voltage. On the other hand, since thetransparent electrode employed in the above method has a lighttransmittance of 80 to 85%, provision of two transparent electrodelayers leads to lowered light transmittance to deteriorate theperformance as a colored display substrate. For overcoming this defect,there is proposed in Japanese Laid-open Patent Application No. 1-22379(1989) a method comprising forming a colored layer on a master plate andtransferring it onto a transparent substrate. However, since thetransfer is effected for each color with this prior-art method, itbecomes necessary to achieve high precision alignment for each transferoperation, thus complicating the production.

On the other hand, in order to meet the demand for high performance ofthe device provided with a color filter, it has been desired to improvecontrast and to prevent color purity from being lowered. In order tosolve this problem, a method of forming a non-light transmitting film ina region of the color filter defined between neighboring pixels has beenproposed. For forming the non-light transmitting film, there are known amethod comprising forming pixels with alignment on a substrate on whicha non-light transmitting film pattern is formed previously, and a methodcomprising forming a non-light transmitting film pattern with alignmenton a substrate on which a pixel pattern is formed previously.

However, since it is necessary with these methods to effect an alignmentoperation between the pixel pattern and the non-light transmittingpattern, it is difficult with this precision to form a pattern ofnon-light transmitting pattern of a coincident size free of the lighttransmitting sections between the pixel patterns. If overlapped portionsare produced, step differences are produced on a color filter, so thatit becomes difficult to produce a color filter excellent in planarity.

With any of the above methods, high precision processing is required foralignment so that it is difficult to cope with the demand for a largerwork size, that is a larger picture size with reduced costs.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method forproducing a color filter in which high precision fine machiningtechnique is not required, the pattern figure of the colored layer has ahigh degree of freedom, non-light transmitting metal layers can bearrayed without gaps between the color filter pixels and the colorfilter size may be increased easily and in which mass production may beachieved easily and simply.

The above and other objects of the invention will become apparent fromthe following description.

According to the present invention, there is provided a method forproducing a color filter comprising the steps of:

(A) forming a photosensitive coating film on a transparent electricallyconductive layer provided on an outermost surface of a substrate havingan alignment film, and exposing the photosensitive coating film to lightin a first irradiation amount through a mask having a predeterminedpattern of a certain light transmittance, and at least once displacingsaid mask to another position on the photosensitive coating film andexposing the photosensitive coating film to light in a secondirradiation amount different from the first irradiation amount throughthe mask,

(B) developing and removing a photosensitive coating film portionexposed to light in one of smallest and largest irradiation amounts forexposing the transparent electrically conductive layer andelectrodepositing a colored coating on the exposed electricallyconductive layer for forming a colored layer thereon, operation ofdeveloping and removing the photosensitive coating film andelectrodepositing the colored coating being repeated in sequence ofdifference in irradiation amounts to form different colored layers,respectively; and

(C) transcribing the colored layers, the transparent electricallyconductive layer and the alignment film onto another substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process chart showing an embodiment of the presentinvention.

FIG. 2 is an enlarged schematic view of a mask employed in Examples ofthe present invention.

FIG. 3 is an enlarged schematic view of a mask employed in Examples ofthe present invention, in which the mask is once displaced laterally toanother position on the photosensitive coating film.

FIG. 4 is an enlarged schematic view of a mask employed in Examples ofthe present invention, in which the mask is twice displaced laterally toother positions on the photosensitive coating film.

FIG. 5 is a schematic view showing a transcription step of the presentinvention.

PREFERRED EMBODIMENTS OF THE INVENTION

In the method for producing a color filter of the present invention, aphotosensitive coating film is formed on a transparent electricallyconductive layer provided on the outermost surface of a substrate havingan alignment film and the photosensitive coating film is exposed tolight through a mask having a predetermined pattern of a certain lighttransmittance. This step is referred to hereinafter as a step A.

According to the present invention, any plate-shaped substrate which isprovided with an alignment film and the outermost surface of which isprovided with a transparent electrically conductive layer, may beemployed.

A material for the substrate may, for example, be metal or aplate-shaped insulator and may specifically include glass, a variety oflaminated plates or a variety of plastic plates or metallic plates. Thesubstrate surface may preferably be smooth in view of the color filterperformance. If necessary, the substrate surface may be ground. Forfacilitating the transcription operation during the subsequent step, arelease layer may be formed between the substrate surface and thealignment film. As the release layer, silicone orpolytetrafluoroethylene thin films may be employed.

The alignment film employed in accordance with the present invention maybe similar to that customarily employed in liquid crystal alignmentfilms.

The material used for the alignment film may preferably be such amaterial as does not affect the performance required of the colorfilter, such as silica as an inorganic material, or polyimide,polyphenylene sulfide, epoxy resin or acrylic resin as organicmaterials. The film thickness of the alignment film may preferably be0.01 to 3 μm, depending on the performance required of the color filter.The alignment film may be formed by e.g. oblique vacuum deposition,grating or rubbing. The latter method is most preferred because it canbe effected after the end of the transcription process. The alignmentfilm may also be formed by polymerization on the substrate surface suchas by plasma polymerization.

The transparent electrically conductive layer employed in the presentinvention may be formed of a material mainly composed of tin oxide,indium oxide, antimony oxide or mixtures thereof, and may preferably be20 to 300 nm in thickness. There is no particular limitation as to themethod of forming the transparent electrically conductive layer and anyof the conventional methods, such as spraying, CVD, sputtering or vacuumdeposition, may be employed. The transparent electrically conductivelayer may preferably be of the highest degree of transparency aspossible in view of the performance required of the color filter.

Although there is no limitation as to the methods of forming thephotosensitive coating film on the transparent electrically conductivelayer of the substrate, it may be formed by application on thetransparent electrically conductive layer by any known method such aselectrodeposition, spraying, dip coating, roll coating, screen printingor spin coating.

As the negative type photosensitive coating for forming the negativetype photosensitive coating film, a negative type photosensitive coatingresin exhibiting film forming capabilities and photosensitivity and aphotopolymerization initiator may be dispersed or dissolved in a solventsuch as an organic solvent or water so as to be used as a coatingmaterial. As the positive type photosensitive coating for forming thepositive type photosensitive coating film, a positive typephotosensitive coating resin exhibiting film coating capabilities andphotosensitivity may be dispersed or dissolved in water or in an organicsolvent so as to be used as a coating material. Dyes and/or pigments maybe contained in the negative or positive type coatings. If the dyesand/or the pigments are of a color hue corresponding to that of thetarget color filter, the number of repetition of the step B laterdescribed may be correspondingly reduced.

The negative type photosensitive coating resin preferably employed inthe present invention may include a prepolymer having photosensitivegroups such as (meth)acryloyl groups, e.g. acryloyl or methacryloylgroup, cinnamoyl groups or mixtures thereof at a terminal and/or sidechain of the molecule, an onium group-containing cationic resin or acarboxylic group-containing anionic resin. The negative typephotosensitive coating resin may have a molecular weight ranging between500 and 10,000.

The prepolymer may preferably be formed from epoxy (meth)acrylate,urethane (meth)acrylate, polyester (meth)acrylate, or mixtures thereof.

The onium group-containing cationic resins may be composed of a mainresin, such as acrylic resin, polyester resin, maleinated oil resin,polybutadiene resin, epoxy resin, urethane resin, polyamide resin ormixtures thereof, and the photosensitive groups and onium groups, suchas amino group, ammonium group, sulfonium group or mixtures thereof,introduced therein. These resins may preferably be processed with anacidic susbstance such as formic acid, acetic acid, propionic acid,lactic acid or mixtures thereof, and solubilized and/or dispersed inwater.

The carboxyl group-containing anionic resins may be composed of theabove mentioned main resin into which carboxylic groups and theaforementioned photosensitive groups are introduced. These resins maypreferably be solubilized and/or dispersed in basic substances, such astriethylamine, diethylamine, dimethylethanol amine, ammonia or mixturesthereof.

There is no particular limitation to the positive type photosensitivecoating resin, if it is dissolved in a developing solution on lightexposure, and may be enumerated by resins including quinone diazidogroups, resins including diazomeldrum's acid or nitrobenzyl ester, orresin compositions including these resins. Specific examples of theseresins include a quinone diazido group-containing cationic resin inwhich the onium groups and hydroxyl groups are introduced into the abovemain resins, to which a quinone diazido sulfonic acid compound is addedfurther by esterification reaction followed by being processed with anacidic substance such as formic acid, acetic acid, propionic acid,lactic acid or mixtures thereof and solubilized and/or dispersed inwater; a quinone diazido group-containing anionic resin in whichcarboxyl groups and hydroxyl groups are introduced into the abovementioned main resins, to which a quinone diazido sulfonic acid compoundis further added by an esterificiation reaction followed by beingprocessed with basic substances e.g. triethylamine, diethylamine,dimethylethanol amine, ammonia or mixtures thereof, and solubilizedand/or dispersed in water; a quinone diazido group-containing resinobtained by reacting a resin having film-forming capability and ahydroxyl group-compound with a quinone diazido compound including aquinone diazido sulfonic acid derivative or an isocyanate group; andresin compositions containing these resins. The mixing ratio for theresin compositions may be optionally selected depending on lightexposure and development conditions.

As the negative type photosensitive coating resin and the positive typephotosensitive coating resin, prepolymers or resins that may besolubilized and/or dispersed in water are most preferred for simplifyingthe process and combating the pollution.

The negative type photosensitive coating resins may also be admixed withlow molecular (meth)acrylates for controlling photosensitive propertiesand viscosity of the coating film. Examples of such (meth)acrylatesinclude 2-hydroxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate,3-phenoxy-2-hydroxypropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,tricyclodecane (meth)acrylate, hexanediol-di(meth)acrylate,trimethylolpropane triacrylate, pentaerythritol triacrylate,dipentaerythritol hexacrylate, tris(acryloyl oxyethyl) isocyanurate, andmixtures thereof. The proportion of these (meth) acrylates is preferablyup to 50 and most preferably up to 30 parts by weight to 100 parts byweight of the negative type photosensitive coating resin. If theproportion of the (meth)acrylates exceeds 50 parts by weight, thecoating becomes undesirably tacky.

The photopolymerization initiator employed in the negative typephotosensitive coating may be any of those known in the art and may beenumerated by benzoins, benzoin ethers, benzylalkyl ketals, benzophenonederivatives, anthraquinone derivatives, thioxanthone derivatives ormixtures thereof. Sensitizers may be added thereto if so desired. Thephotopolymerization initiator may be added in an amount of 0.05 to 30and preferably 0.1 to 20 parts by weight to 100 parts by weight of thenegative type photosensitive coating resin. If the amount of theinitiator is less than 0.05 part by weight, photocuring properties fallshort, whereas, if it exceeds 30 parts by weight, curing proceedsexcessively and hence the coating film becomes poor in strength, whileeconomic advantages are also lost.

The organic solvent used for dispersing or dissolving the components ofthe negative and positive type photosensitive coating resins may be anyof those capable of dispersing or dissolving the above mentionedprepolymers or resins. Examples of the solvents include glycol ethers,such as ethyleneglycol monobutyl ether, ethyleneglycol monohexyl ether,ethyleneglycol monophenyl ether, propyleneglycol monomethyl ether,propyleneglycol monophenyl ether, diethyleneglycol dimethyl ether ortriethyleneglycol dimethyl ether; ketones such as acetone, methylethylketone, methylisobutyl ketone, cyclohexanone, isophorone or N-methylpyrrolidone; ethers such as dibutyl ether, dioxane or tetrahydrofuran;alcohols such as methoxy butanol, diacetone alcohol, butanol, octanol orisopropanol; hydrocarbons such as toluene, xylene, cyclohexane orhexane; esters such as ethyl acetate, butyl acetate, 2-methoxyethylacetate, 2-methoxypropyl acetate or ethyl benzoate; acid amides such asdimethyl formamide, N,N-dimethyl acetoamide or dimethyl sulfoxide, andmixtures thereof.

These organic solvents may be added during solubilization or dispersionin water of the above mentioned cationic or anionic resins for improvingbath stability or smoothing coating films.

Although the color hue of the dyes and/or pigments occasionally added tothe above mentioned negative or positive type photosensitive coating maybe suitably selected depending on the particular application, it ispreferably dark and, above all, black, dark navy-blue, dark purple ordark brown, for avoiding light leakage.

The dyes and/or the pigments are preferably so selected as not to lowerthe stability and occasionally electrodeposition properties as well asdurability of the coating. For this reason, oil soluble or dispersibledyes, such as azo, anthraquinone, benzodifuranone, condensed methineseries dyes, or mixtures thereof, are preferred. The pigments may beexemplified by organic pigments, such as azo lake organic pigments,quinacridone organic pigments, phthalocyanine organic pigments,isoindolinone organic pigments, anthraquinone organic pigments orthioindigo organic pigments; chrome yellow, iron oxide, chromevermilion, chrome green, ultramarine, prussian blue, cobalt blue, cobaltgreen, emerald green, titanium white, carbon black or mixtures thereof.As for the color hue of the dyes and pigments, reference is had to"COLOUR INDEX" whenever necessity arises.

The amount of the dyes and/or the pigments is suitably selecteddepending on the application, color hue, the type of the dyes and/or thepigments or the film thickness of the photosensitive coating. The amountmay preferably be 3 to 70 wt. % and more preferably 5 to 60 wt. % basedon the total photosensitive coating.

Depending on the type and the amounts of the dyes and/or pigments, theproduced coating film may be rendered light transmitting or lightintercepting according to the intended applications. For example, blacktinted light-intercepting coating film may be produced by using 3 to 50wt. % of carbon black, as pigments, based on the total amount of thenegative or positive type photosensitive coating. the black-huedlight-intercepting coating film is particularly desirable for preventinglight leakage. The photosensitive coating may be admixed with variousassistant agents, such as dispersants for the dyes and/or the pigments,levelling agents for improving smoothness of the coating film, viscosityadjustment agents or defoaming agents.

For producing the negative type photosensitive coating, the negativetype photosensitive coating resins, the photopolymerization initiatorand the solvent are sufficiently dispersed, using a dispersionapparatus, such as customary sand mills, roll mills or attriters. Thepositive type photosensitive coating may be prepared by mixing anddispersing the resins for the positive type photosensitive coating andthe solvent in the same manner as for the negative type coating. Thedyes, pigments, acidic or basic substances, dispersants, levellingagents for improving smoothness of the coating film, viscosityadjustment agents or defoaming agents may be mixed and dispersed asneeded. There is no limitation to the film thickness of thephotosensitive coating films formed by the photosensitive coating andthe film thickness may be suitably selected depending on the performancedesired of the color filter. The dry film thickness may be usually 0.3to 20 μm and preferably 1 to 15 μm. The film thickness may be adjustedby controlling, for example electrodeposition conditions, such asvoltage, electrodeposition time and bath temperature. However, filmthickness adjustment may be usually made under the same conditions asthose for electrodeposition coating of colored coatings, as will beexplained subsequently. Incidentally, when the negative typephotosensitive coating film is not employed as a colored layer, it ispreferred that the coloring agents be not added and the film thicknessbe as thick as 5 to 15 μm to reduce hindering action against curing dueto oxygen.

For exposing the photosensitive coating film to light, the substrate isexposed to light through a mask having a predetermined pattern of acertain light transmittance. The mask is then displaced at least onceand the photosensitive coating film is exposed to light with anirradiation amount different from that prior to the displacement. Bydisplacement herein is meant changing the relative position between themask and the substrate. Thus the mask may be moved with the substrateremaining stationary or the substrate may be moved with the maskremaining stationary, or both the substrate and the mask may be moved.

According to the present invention, the mask having the predeterminedpattern preferably has a light-transmitting portion or portions (patternblock or blocks) and a non-transmitting portion or portions. It ispreferred that the pattern blocks be not overlapped after apredetermined number of times of displacement. Therefore, the spacingbetween adjacent pattern blocks needs to be such that the pattern blocksbe not overlapped at each exposure to light after mask displacement. Ifa light-intercepting portion has to be provided, the interval betweenthe pattern blocks needs to be equal to [(the number of times ofmovement plus 1)×pattern block width]. Explaining the mask further byreferring to the drawings, a first light exposure operation is carriedout using the mask having the pattern shown in FIG. 2, and the mask isdisplaced transversely, as shown in FIG. 3, for exposing the portions ofthe substrate to light, which have not been exposed to light, with anirradiation amount different from that of the preceding light exposure.The mask is then displaced transversely, as shown in FIG. 4, forexposing the substrate with an irradiation amount different from that ofthe preceding first and second light exposure operations. Since thepattern block are not overlapped during each light exposure operation,the states of light exposure which differ in four stages, inclusive ofthe portions not exposed to light, are produced.

There is no particular limitation to the directions of the maskdisplacement which may be the fore-and-aft direction or the transversedirection. The positions and the relative distance of the pattern blocksof the mask may be determined by the number of times, direction or thedistance of the mask displacement.

According to the present invention, the mask is displaced at least onceand any desired number of times as a function of the number of thecolored layers and the occasionally produced light-intercepting layersdesired to be produced on a substrate. If the mask is displaced once,three states of light exposure different in three states may be producedinclusive of the portions not exposed to light. Similarly, if the maskis displaced twice or three times, four or five different states oflight exposure may be produced.

According to the present invention, each light exposure operation iscarried out in an irradiation amount different from the irradiationamount(s) used in the preceding light exposure operation(s). There is noparticular limitation to means for changing the irradiation amounts andany of the methods of changing the light exposure time, the distance ofthe light source to the substrate or the output of the light source, maybe employed.

The difference in the irradiation amounts used in the light exposureoperations may be selected depending on the conditions of light exposureand on the developing conditions as later explained. Since a largerrelative difference in the density of cross-linkage produced by thelight irradiation is preferred because a larger difference in solubilityrelative to the developing solution is thereby produced, it is preferredto increase the irradiation amount of the largest light irradiationamount to increase the density of cross-linkage (degree ofdecomposition) of the photosensitive coating film and to diminish theirradiation amount of the smallest light irradiation to lower thedensity of cross-linkage (degree of decomposition) of the photosensitivecoating film. Although there is no particular limitation to the relativedifference in the irradiation amounts, it is usually preferred toprovide a significant relative difference of not less than 5%.

The above-mentioned light exposure may be performed using an apparatuscapable of generating a large amount of ultraviolet rays, such as a highpressure mercury lamp, an ultra high pressure mercury lamp or a metalhalide lamp. However, a light radiation source generating a radiationother than UV rays may be employed. The conditions for light exposuremay be suitably selected depending on the negative or positive typephotosensitive coatings, the light exposure devices or theabove-mentioned masks.

In the method of the present invention, the operation of developing andremoving a photosensitive coating film portion exposed to light in oneof the smallest and largest irradiation amounts for exposing thetransparent electrically conductive layer and electrodepositing acolored coating on the exposed electrically conductive layer for forminga colored layer thereon. The operations of developing and removing thephotosensitive coating film and electrodepositing the colored coatingare repeated in the sequence of difference in the irradiation amounts toform plural colored layers, respectively (referred to as a step B). Ifthe photosensitive coating film is a negative type photosensitivecoating film, the negative type photosensitive film portions on thesubstrate in register with the pattern blocks with the smallestirradiation amount are selectively developed and removed, and a coloredcoating is electrodeposited on the exposed electrically conductive layerto form a colored layer. The negative type photosensitive film portionsin register with the pattern blocks of the second smallest irradiationamount are then selectively developed and removed, and a differentcolored layer is electrodeposited on the newly exposed portions of theelectrically conductive layer. These operations are repeated in thissequence a desired number of times for producing a desired number ofdifferent colored layers.

If the photosensitive coating film is of a positive type, the positivetype photosensitive coating film portions in register with the largestirradiation amounts are selectively developed and removed and a coloredcoating is electrodeposited on the exposed electrically conductive layerto form a colored layer. The positive type photosensitive coating filmportions in register with the second largest irradiation amounts arethen selectively developed and removed and a different colored coatingis electrodeposited on the newly exposed portions of the electricallyconductive layer to form a different colored layer. These operations maybe repeated a desired number of times for producing a desired number ofdifferent colored layers.

The conditions for selectively developing and removing thephotosensitive coating film may be changed depending on the volume oflight exposure, solubility of the photosensitive coating in thedeveloping solution, the types and the concentrations of the developingsolution, development time and temperatures. Thus, the conditions may besuitably selected for the resin used for the preparation of thephotosensitive coating. Specifically, aqueous solutions containingdissolved acidic materials may be used as a developing solution when thecationic resin is used as a component of the negative photosensitivecoating. The acidic materials include organic acids, such as formicacid, acetic acid, propionic acid or lactic acid; inorganic acids, suchas hydrochloric acid or phosphoric acid; and mixtures thereof. If lacticacid is used as a developing solution, it may be used at a concentrationusually of 0.01 to 50 wt. % and preferably 0.05 to 25 wt. %. Thedeveloping temperature is usually 10° to 70° C. and preferably 15° to50° C. and the developing time is usually 2 to 600 seconds andpreferably 4 to 300 seconds. As a developing solution in case ofemploying an anionic resin as a component of the negative typephotosensitive coating and in case of employing the positive typephotosensitive coating, an aqueous solution containing basic substancesdissolved therein, may be employed. The basic substances may includesodium carbonate, sodium hydrogen carbonate, sodium metasilicate,tetraalkyl ammonium hydroxide, sodium hydroxide, potassium hydroxide andmixtures thereof. If an aqueous solution of sodium carbonate is used asa developing solution, sodium carbonate may be used in a concentrationrange of 0.01 to 25 wt. % and preferably 0.05 to 20 wt. % fordevelopment. The development time usually is selected within a range of2 to 600 and preferably 4 to 300 seconds generally at 10° to 70° C. andpreferably 15° to 50° C. For the developing solutions, organic solventssuch as alcohols, glycol ethers, ketones, chlorinated hydrocarbons ormixtures thereof, may be employed. Surfactants or defoaming agents mayalso be added to these developing solutions for improving wettability oranti-foaming properties. Aqueous developing solutions are preferablyemployed in view of non-toxicity and sanitation in working environments.

After the development, colored coatings are electrodeposited on theexposed transparent electrically conductive layer for forming a coloredlayer.

In preparing the colored coating, cationic resins, anionic resins orphotocurable resins are used as a film-forming component, and dyesand/or pigments are added as a colorant component. Acidic or basicsubstances may also be employed for dissolving and/or dispersing thesecomponents in water. Organic solvents may be added for facilitatingdissolution and/or dispersion of the resins in the colored coating forimproving bath stability or for producing smooth coating films.

The cationic resins may for example be resins composed of the mainresins used in the photosensitive coating into which onium groups suchas ammonium, sulfonium groups or amino groups are introduced, such asresins solubilized or dispersed in water with an acidic substance, suchas formic acid, acetic acid, propionic acid, lactic acid or mixturesthereof.

The anionic resins may for example be resins composed of the main resinsused in the photosensitive coating into which carboxyl groups, etc. areintroduced, and may for example be resins solubilized or dispersed inwater with basic substances such as triethylamine, diethylamine,dimethylethanol amine, ammonia or mixtures thereof.

As the photocurable resins, those prepolymers or resins containingacryloyl groups, methacryloyl groups, cinnamoyl groups or mixturesthereof, that are used in the photosensitive coating film in the step Aand that are suited for electrodeposition, may be employed. The abovementioned photopolymerization initiators may also be employed incombination.

The colored coatings employed in step B may be different in type, colorhue, color concentration or color brightness in the regions exhibitingdifferent light transmittances. Alternatively, the same colored coatingsmay be used in common for these regions.

The color hue of the colored coating may be selected suitably, dependingon particular applications. For example, the photosensitive coating usedin step A, the colored coating used in step B and the colored coatingsused in step B in case of repeating the electrodepositing processseveral times, may be those exhibiting different color hues.

The dyes and/or pigments used in the colored coatings may be suitablyselected depending on the targeted color hue. It is, however, preferredto use those dyes and/or pigments which are not unsatisfactory intransparency, stability, electrodeposition properties and durability ofthe coating film. Particularly preferred are those dyes or pigmentswhich may be mixed as the occasion may demand in the above mentionedphotosensitive coatings. Two or more of the aforementioned dyes and/orpigments may be mixed depending on the objective color hue as far as theproperties of the dyes and/or pigments are not deteriorated.

In the preparation of the colored coatings, resins, dyes and/orpigments, acidic or basic substances, organic solvents, dispersants forthe dyes or pigments, levelling agents for improving smoothness of thecoating films, viscosity controlling agents or anti-foaming agents aremixed together and dispersed sufficiently in a conventional dispersiondevice such as sand mill, roll mill or attriter. The resultingdispersion is diluted in water to a predetermined concentration of about4 to 25 wt. % and preferably to 7 to 20 wt. % of solid content toproduce a coating suitable for electrodeposition. The so-producedcoating may be applied on the electrically conductive layer byelectrodeposition for providing a colored layer.

There is no particular limitation to the film thickness of the coloredlayer, which may be suitably selected depending on the performancerequired of a color filter. However, the dry thickness is usually 0.3 to5 μm and preferably 1 to 3 μm.

Although the conditions of electrodeposition may be suitably selecteddepending on the types of the colored coatings and film thickness of thecolored coating films, the electrical voltage is usually 5 to 500 V dcand preferably 10 to 300 V dc, the electrodeposition time is usually 5to 300 sec and preferably 10 to 200 sec and the liquid temperature isusually 10° to 35° C. and preferably 15° to 30° C. After lapse of theelectrodeposition time sufficient to produce a desired film thickness,current conduction is discontinued and the substrate is taken out of thebath. The substrate is freed of excess bath liquid by washing with waterand dried to produce the colored layer.

Although the drying conditions may be selected suitably depending on theconditions of the subsequent process steps, it is usually preferred thatthe conditions be such that surface moisture is dried, for example, thedrying time be of the order of 1 to 20 minutes and preferably 2 to 10minutes at a temperature of 120° C. or lower and preferably 30° to 100°C. If the drying temperature is higher than 120° C., the photosensitivecoating film is occasionally cured under heat to raise difficulties inthe subsequent development process.

According to the present invention, a step of developing and removing anegative type photosensitive coating film or a positive typephotosensitive coating film in at least one of plural light-exposedportions with different irradiation amounts to expose an electricallyconductive layer, and selectively forming a metal layer thereat,referred to hereinafter as step C, may be carried out, whenever thenecessity arises. In addition, a step of electrodepositing a coloredcoating on the metal layer formed by step C for forming a colored layerwith a view to inhibiting the reflection of the metal layer andproviding for the same uniform thickness for the metal layer and thecolored layer, referred to hereinafter as step D, may also be carriedout. Above all, the metal layer may preferably be formed selectively inan interstice region between the patterns of the colored layers producedin step B. If the photosensitive coating film is formed using a negativetype photosensitive coating, it is preferred to carry out the steps A,C, D and B in this sequence. If the photosensitive coating film isformed using a positive type photosensitive coating, it is preferred tocarry out the steps A, B and C in this order, and to carry out the stepD subsequently, if necessary. For improving the clearness of an imagewhich may be obtained by using the color filter, it is preferred to formthe metal layer as the light-intercepting layer accurately and, forforming the metal layer accurately, it is preferred to form the metallayer before forming the colored layer. Specifically, if thephotosensitive coating film is formed using the negative typephotosensitive coating, it is preferred to develop the portion with theleast amount of light exposure to form the metal layer before the stepB. Although the colored coating is electrodeposited on the metal layerduring the step D, it is practically not hindersome. The color hue ofthe colored layer formed on the metal layer is preferably achieved withthe use of a dark-hued colored coating among those that may be used instep B.

The metal layer may preferably be formed by developing and removing thephotosensitive coating film remaining on at least one patterned portionand/or on the substrate, before or after formation of the colored layerat step B, and by processing the exposed electrically conductive layerby an electroplating method or an electroless plating method. Thisprocessing may be carried out appropriately to conform to theperformance required of a color filter with the use of any of a varietyof commonly employed plating solutions.

Among metals which may be used as the metal layer, there are a varietyof customary metal materials which may be used for plating and which areselected from copper, nickel, silver, gold and chromium, an alloy of twoor more of these metals, and metals obtained by mixing two or more ofthese metals in a plating solution. The thickness of the metal layer maybe suitably selected depending on the performance required of the colorfilter and may be 10 nm to 5 μm, preferably 10 nm to 3 μm. The metallayer may preferably be formed so as to be of a thickness equal to thatof the colored layer since a planar color filter may thereby beproduced. However, if the metal layer is formed by an electroplatingmethod, the metal layer is of a lesser thickness than the colored layer.For this reason, the step D is preferably carried out further to adjustthe film thicknesses.

The solution which may be used for forming the metal layer is preferablyadjusted as to its pH value by selection of the sequence of carrying outthe step C. Specifically, if the metal layer is formed during or afterformation of the colored layer of step B, it is preferred to use aplating solution which is close to neutrality, above all, which has a pHvalue in the range of 5 to 9. If the cationic electrodeposition typecoating be used as the above-mentioned colored coating, it is preferredto use a weakly alkaline plating solution within the above-mentioned pHrange, whereas if the anionic electrodeposition type coating is used, itis preferred to use a weakly acidic plating solution within theabove-mentioned pH range. On the other hand, if the metal layer isformed after formation of all of the colored layer, followed by dryingon heating, the pH value other than the neutral range of from 5 to 9 mayalso be employed. Specifically, if the cationic electrodeposition typecoating is used as the colored coating, any alkaline plating solutionmay be employed, whereas if the anionic electrodeposition type coatingis used, any acidic plating solution may be employed. If the metal layeris formed before forming the colored layer, the plating solution closeto a neutral range, above all, that having the pH valur of 5 to 9, ispreferred. If the photosensitive coating film is of the positive type,it is preferred to use a weakly acidic plating solution within theabove-mentioned pH range. On the other hand, if the photosensitivecoating film is of the anionic electrodeposition negative type, it ispreferred to use a weakly acidic plating solution within theabove-mentioned pH range. If the photosensitive coating film is of acationic electrodeposition negative type, it is preferred to use aweakly alkaline plating solution within the above-mentioned pH range.

Since the metal layer is formed, such as by plating, on a selectivelyexposed portion of the electrically conductive layer, by theabove-mentioned step C, the metal layers may be formed in theinterstices of the colored layers in a self-aligned manner. Such colorfilter, capable of improving contrast and color purity, also has thefunction of an auxiliary electrode line and the function of reducing theheating within the cell or the signal delay otherwise caused on a largedisplay screen.

The method of the present invention also includes the step oftranscribing the colored layers obtained in step B together with thetransparent electrically conductive layer and the alignment film ontoanother substrate or a transcription substrate (referred to as a stepZ). If the above-mentioned step C is carried out, the method of thepresent invention includes the step of transcribing the colored layersand the metal layer onto the transcription substrate. If theabove-mentioned step D is carried out, the method of the presentinvention includes the step of transcribing the colored layers, a metallayer and another colored layer formed on the metal layer onto thetranscription substrate.

There is no particular limitation to the transcription substrate whichmay be suitably selected from a transparent substrate, asemi-transparent substrate and a colored substrate, according to usageand application. Preferably, a transparent substrate of glass orplastics, such as glass, polyester, polysulfone, cellulose triacetate,polycarbonate, polyimide, polystyrene or polymethyl pentene, may beemployed.

For transcription, a method of pressing the colored layer against thetranscription substrate may be employed. For pressing, a press or acoated roll may be used, occasionally under heating. If the coloredlayer is photosensitive, the transcription may be carried out by curingthe colored layer with light irradiation. A transparent adhesive such asa hot melt adhesive, a photocurable adhesive or a pressure-sensitiveadhesive may be applied on the surface of the transcription substrate tofacilitate the transcription. The substrate may be re-heated orre-irradiated with light after the transcription step to achievesufficient curing to improve weatherability and resistance to chemicals.The re-heating, if conducted, is performed preferably at 50° to 250° C.and more preferably at 100° to 200° C. for 5 minutes to 1 hour andparticularly for 10 to 30 minutes. The substrate may be re-used aftertranscription.

The desired color filter may be prepared by the above-mentioned steps A,B and Z and occasionally by the step C and by the step D. However, ifnecessary, heating, curing or photocuring may be carried out for furtherimproving weatherability and resistance to chemicals. The heating orcuring conditions include the temperature of from 100° to 250° C. andpreferably 150° to 250° C. and the operating time of five minutes to onehour and preferably 15 to 40 minutes.

The process of the present invention are shown in the drawings merelyfor the sake of illustration.

FIG. 1 shows the process according to an embodiment of the presentinvention.

FIG. 2 shows, in an enlarged schematic view, a mask which is employed inthe present invention and which may be displaced up to twice. 1 denotesa region of the mask with substantially zero transmittance andcorresponding to a light-intercepting film of the mask. 2 denotespattern blocks exposed to light on first light irradiation.

FIG. 3 shows the mask of FIG. 2 displaced once transversely. In FIG. 3,3 denotes mask portions to be exposed to light on second lightirradiation.

FIG. 4 shows the mask displaced further transversly from the state shownin FIG. 3. In FIG. 4, 4 denotes mask portions to be exposed to light onthird light irradiation.

FIG. 5 shows the transcription process step, in which 5 denotes asubstrate, 6 an alignment film, 7 a transparent electrically conductivelayer, 8 a colored layer and a metal layer, and 9 a transcriptionsubstrate.

A negative type or positive type photosensitive coating film is formedon a transparent electrically conductive layer formed on the outermostsurface of a substrate on which the alignment film is also formed. Thesubstrate is dried and irradiated with light of e.g. 400 mJ, with theinterposition of the mask shown in FIG. 2, by way of a first lightexposure operation. The mask is then displaced transversely, as shownfor example in FIG. 3, and irradiated with the light of e.g. 50 mJ, byway of a second light exposure operation. The mask is then displacedtransversely, as shown for example in FIG. 4, and irradiated with thelight of e.g. 100 mJ, by way of a third light exposure operation.

A first development operation is then performed, in which the portionsirradiated with the smallest amount of light irradiation are developedand removed if the photosensitive coating film is formed using thenegative type photosensitive coating, while the portions irradiated withthe largest amount of light irradiation are developed and removed if thephotosensitive coating film is formed using the positive typephotosensitive coating. A colored coating of a first color iselectrodeposited on the thus exposed electrically conductive layer toform a colored layer or a light-intercepting layer by plating. Thesubstrate thus processed is washed with water.

The second development operation is then carried out under conditionsdifferent from those used in the first development operation. At thistime, the portions with the second smallest irradiated amounts aredeveloped and removed when the photosensitive coating film is formedusing the negative type photosensitive coating and portions with thesecond largest irradiated amounts are developed and removed when thephotosensitive coating film is formed using the positive typephotosensitive coating. A colored coating of a second color iselectrodeposited on the thus exposed electrically conductive layer toform a colored layer. The substrate is then washed with water.

The third development operation is then carried out under conditionsdifferent from those used in the first and second developmentoperations. At this time, the portions with the third smallestirradiated amounts are developed and removed if the photosensitivecoating film is formed using the negative type photosensitive coatingand the portions with the third largest irradiated amounts are developedand removed if the photosensitive coating film is formed using thepositive type photosensitive coating. A colored coating of a third coloris electrodeposited on the thus exposed electrically conductive layer toform a colored layer. The substrate is then washed with water.

The fourth development operation is then carried out under conditionsdifferent from those used in the first to third development operations.At this time, the portions with the largest irradiated amount aredeveloped and removed if the photosensitive coating film is formed usingthe negative type photosensitive coating, and the portions with thesmallest irradiated amounts are developed and removed if thephotosensitive coating film is formed using the positive typephotosensitive coating. A coating of a fourth color is electrodepositedon the thus exposed electrically conductive layer to form a coloredlayer or a light-intercepting metal layer by plating. The substrate isthen washed with water.

The alignment film 6, the transparent electrically conductive layer 7,the colored layer and the metal layer 8, thus formed on the substrate 5,are transcribed to a transcription substrate 9 to produce a color filterof the present invention. Although the light-intercepting layer may alsobe formed in place of the colored layer after the second and/or thirddevelopment operations, it is necessary to carry out the step of formingat least the colored layer after the first to fourth developmentoperations. A colored layer may be additionally formed on the metallayer formed after the first to fourth development operations fortranscription of the metal layer and the colored layer formed on themetal layer, or for transcription of the colored layer formed on themetal layer.

With the method for producing a color filter of the present invention,the degree of freedom in the pattern shape of the colored layers may beincreased without requiring fine processing techniques, while thenon-transmitting film may also be formed easily and the color filter mayalso be increased in size. Thus the color filter may be produced easilyin large quantities.

EXAMPLES OF THE INVENTION

The present invention will be explained hereinbelow with reference toSynthesis Examples and Examples which are given only for illustrationand are not intended for limiting the invention.

SYNTHESIS EXAMPLE 1 Synthesis of Cationic Positive Type PhotosensitiveResin (X-1) Synthesis of Unsaturated Compound (x-1)

148 parts of glycidol, 0.8 part of dibutyl tin dilaurylate, 0.2 part ofhydroquinone monomethyl ether and 82 parts of 2-ethoxyethyl acetate werecharged into a 1 lit separable flask fitted with a thermometer, anagitator, a reflux cooling tube, a gas inlet pipe and a dropping funnel,and the temperature was raised to 50° C. 319 parts ofmethacryloyloxyethyl isocyanate were added dropwise over an hour as airwas blown into the system and reaction was carried out until absorptionof the isocyanate groups in IR absorption spectrum substantiallydisappeared. 276 parts of 4-hydroxy benzoic acid were added, and thetemperature was raised to 110° C. After it was confirmed that the acidvalue was not more than 5 and the epoxide equivalent weight was not lessthan 11,000, the reaction was discontinued to produce an unsaturatedcompound (x-1).

Synthesis of Cationic Positive Type Photosensitive Resin (x-2)

238 parts of diethylene glycol monoethyl ether were charged into a 1 litseparable flask fitted with a thermometer, an agitator, a reflux coolingtube and a dropping funnel, and the temperature was raised to 130° C.Into this mixture, a mixed solution composed of 145 parts of (x-1), 83parts of isobutyl methacrylate, 167 parts of ethyl acrylate, 78 parts ofethyl methacrylate, 41 parts of dimethylaminoethyl methacrylate and 12parts of t-butyl peroxy-2-ethyl hexanoate were added dropwise over threehours. After lapse of 30 minutes, a mixed solution of 25 parts ofdiethylene glycol monoethyl ether and 2 parts of t-butyl peroxy-2-ethylhexanoate was added dropwise over 30 minutes. The resulting mass wasmaintained at this temperature for two hours to terminate the reaction.500 parts of the produced acrylic resin solution were taken into a 3 litseparable flask fitted with a thermometer, an agitator, a reflux coolingtube, a nitrogen inlet pipe and a dropping funnel. Into this mixture1570 parts of acetone and 60.1 parts of 1,2-naphthoquinonediazido-5-sulfonyl chloride were added, and the resulting mass wasagitated throughly at room temperature. Into the resulting mixture, 26.7parts of triethylamine were added dropwise over an hour, and reactionwas continued for further two hours. The produced solution was filteredto remove impurities. The resulting mass was added dropwise over aboutone hour into a 20-fold quantity of well-agitated water and precipitatedresins were recovered. After removal of the moisture under reducedpressure, a brownish cationic positive type photosensitive resin (x-2)was produced.

Synthesis of Cationic Positive Type Photosensitive Coating (X-1)

500 g of a cationic positive type photosensitive resin (x-2) weredissolved in 333.3 g of methylethylketone. 11.7 g of acetic acid wereadded as a neutralizer and the resulting mass was agitated sufficientlyand homogenized. As deionized water was added gradually, the resultingmixture was agitated vigorously by a high-speed mixer to effectdispersion in water to prepare an aqueous solution (X-1) of a cationicpositive type photosensitive coating (cationic electrodeposition type).

SYNTHESIS EXAMPLE 2 Synthesis of Anionic Positive Type PhotosensitiveCoating (X-2) Synthesis of Anionic Resin (x-3)

1,000 g of "NISSEKI POLYBUTADIENE B-1000" (manufactured by NIPPONPETROCHEMICALS CO., LTD.; number average molecular weight, 1,000; iodinevalue, 430; content of 1,2-linkage, 65%), 751 g of maleic anhydride, 10g of xylene and 5.0 g of trimethyl hydroquinone, were charged into a 3lit separable flask fitted with a thermometer, an agitator, a refluxcooling tube and a nitrogen blowing pipe, and reaction was carried outat 190° C. for 5 hours under nitrogen. After non-reacted maleicanhydride and xylene were distilled off, maleinated polybutadiene with atotal acid value of 480 mg KOH/g was produced.

Then, 500 g of the maleinated polybutadiene, 218 g of phenoxyethanol and205 g of diethylene glycol dimethyl ether were charged into a 2 litseparable flask fitted with a reflux cooling tube, and dissolvedhomogeneously. Reaction was then carried out under nitrogen at 130° C.for three hours. Then, 61 g of benzylamine were added dropwise for 30minutes at the same temperature and the temperature was raised to 165°C. Reaction was carried out at this temperature for seven hours toproduce a solution of an anionic resin (x-3) containing half ester andimide groups.

Synthesis of Photosensitive Resin (x-4)

1000 g of "NISSEKI POLYBUTADIENE B-1000" (manufactures by NIPPONPETROCHEMICALS CO., LTD.; number average molecular weight, 1,000; iodinevalue, 430; content of 1,2-linkage, 65%), 388 g of maleic anhydride, 10g of xylene and 3.0 g of trimethyl hydroquinone were charged into a 3lit separable flask fitted with a thermometer, an agitator, a refluxcooling tube and a nitrogen blowing pipe, and reaction was carried outat 190° C. for 5 hours under nitrogen. After non-reacted maleicanhydride and xylene were distilled off, maleinated polybutadiene with atotal acid value of 320 mg KOH/g was produced.

Then, 500 g of the maleinated polybutadiene and 300 g of phenoxyethanolwere charged into a 2 lit separable flask fitted with a thermometer, anagitator, a reflux cooling tube and a nitrogen blowing tube anddissolved homogeneously. Reaction was then carried out under nitrogen at130° C. for three hours. After cooling to room temperature, 149 g of2-(2-aminoethylamino)ethanol were added dropwise over an hour. Thetemperature was then raised to 125° C., at which temperature thereaction was carried out for four hours to produce a solution ofpolyamine resin containing imido groups.

Into a 5 lit separable flask fitted with a reflux cooling tube werecharged 269 g of 1,2-naphthoquinone azido sulfonyl chloride, 1900 g ofdioxane and 300 g of "KYOWAAD 1000" manufactured by KYOUWA CHEMICALIND.. Then, 645 g of the polyamine resin solution were added dropwise at30° C. over two hours and reaction was carried out at this temperaturefurther for five hours. After the produced solution was filtered, 440 gof phenoxy ethanol was added and dioxane was removed under reducedpressure to produce a photosensitive resin (x-4).

The produced resin (x-4) in solution contained 150 mg equivalent ofnaphthoquinone diazido groups per 100 g of resin, and the non-volatilecontent amounted to 60.0 wt. %.

Synthesis of Anionic Positive Type Photosensitive Resin (x-5)

750 g of the (x-3) resin solution and 670 g of the (x-4) photosensitiveresin were mixed thoroughly followed by adding 60 g of triethylamine forsufficient neutralization to produce an anionic positive typephotosensitive resin (x-5) in solution.

Synthesis of Anionic Positive Type Photosensitive coating (X-2)

Deionized water was added gradually to 500 g of a solution of an anionicpositive type photosensitive resin (x-5) and the resulting mixture wasagitated vigorously with a high-speed mixer to effect dispersion inwater for preparing an aqueous solution of an anionic positive typephotosensitive coating (X-2) of an anionic electrodeposition type.

SYNTHESIS EXAMPLE 3 Synthesis of Cationic Negative Type PhotosensitiveCoating (X-3) Synthesis of Amine-added Expoxidated Polybutadiene (x-6)

1,000 g of epoxidated liquid polybutadiene, manufactured by NIPPONPETROCHEMICALS CO., LTD. under the trade name of "E-1000-8", with anumber average molecular weight of 1,000 and an oxirane oxygen contentof 8%, were charged into a 2 lit separable flask, fitted with athermometer, a stirrer and a reflux cooling pipe. After replacing theatmosphere within the system by nitrogen, 231.2 g of methylethanol aminewere added and reaction was carried out at 170° C. for five hours.Non-reacted methylethanol amine was then distilled off under reducedpressure to produce amine-added epoxidated polybutadiene (x-6) with anamine value of 230.4 mmol/100 g.

Synthesis of Unsaturated Group-Containing Isocyanate Compound (x-7)

435.5 g of 2,4-tolylene diisocyanate and 266.1 g of diethylene glycoldimethyl ether were charged into a 2 lit round-bottom flask, which mightbe heated and cooled and which was fitted with a thermometer, a stirrer,a reflux cooling pipe and a dropping funnel. After heating to 40° C.,362.8 g of 2-hydroxyethyl acrylate were added dropwise from the droppingfunnel. 200 ppm of p-benzoquinone was also added at this time. Sincesome heat was evolved due to dropwise addition of 2-hydroxyethylacrylate, the system was occasionally cooled for maintaining theconstant temperature. After the end of the dropwise addition of2-hydroxyethyl acrylate, the temperature was raised to 70° C., at whichtemperature the reaction was carried out for three hours. After the IRabsorption spectral analyses revealed that the absorption intensity ofthe isocyanate groups was decreased to about one half that before startof the reaction, the reaction system was cooled to produce anunsaturated group-containing isocyanate compound (x-7).

Synthesis of Cationic Resin (x-8)

500 g of (x-6) were dissolved in 166.7 g of diethylene glycol dimethylether in a 2 lit separable flask. 713.4 g of (x-7), in which isocyanategroups are contained in an amount of 0.8 equivalent to 1 equivalent ofhydroxyl groups in (x-6), were added dropwise at 40° C., at whichtemperature the reaction was carried out for one hour. The IR absorptionspectral analyses indicated that the isocyanate groups had disappeared.A cationic resin (x-8), in which (x-7) was added to (x-6), was produced.

Synthesis of Cationic Negative Type Photosensitive Coating (X-3)

To 500 g of the cationic resin (x-8) were added 27.0 g of "IRGACURE 907"manufactured by CIBA GEIGY INC. and 3.0 g of "KAYACURE DETX"manufactured by NIPPON KAYAKU CO. LTD., as photopolymerizationinitiators, under agitation, and 16.7 g of acetic acid were added to theresulting mass as a neutralizer. The resulting mixture was agitatedthoroughly and re-homogenized. Deionized water was added gradually tothe homogenized mass and the resulting mixture was agitated vigorouslyby a high-speed mixer to effect dispersion in water to prepare anaqueous solution of the cationic negative type photosensitive coating(X-3) of the cationic electrodeposition type.

SYNTHESIS EXAMPLE 4 Synthesis of Anionic Negative Type PhotosensitiveCoating (X-4) Synthesis of Half-Esterified Product (x-9) solution

1,000 g of "NISSEKI POLYBUTADIENE B-1000", trade name of a productmanufactured by NIPPON PETROCHEMICALS CO., LTD., with a number averagemolecular weight of 1,000, an iodine value of 430, and 1,2-linkage of 65percent, 554 g of maleic anhydride, 10 g of xylene and 3.0 g oftrimethyl hydroquinone were charged into a 3 lit separable flask, fittedwith a thermometer, a stirrer, a reflux cooling pipe and a nitrogenblowing tube, and reaction was carried out under nitrogen at 190° C. forfive hours. After non-reacted maleic anhydride and xylene were distilledoff, maleinated polybutadiene with a total acid value of 400 mg KOH/gwas produced.

Then, 400 g of the maleinated polybutadiene and 188.5 g of diethyleneglycol dimethyl ether and 0.4 g of hydroquinone were charged into a 2lit flask fitted with a reflux cooling tube and the temperature wasraised to 80° C. After the mixture was dissolved uniformly, 165.6 g of2-hydroxyethyl acrylate and 20 g of triethylamine were added andreaction was carried out at 80° C. for two hours to produce ahalf-esterified product (x-9) in solution. The total acid value of theproduced half-esterified product (x-9) in solution was 105 mg KOH/g andthe non-volatile content amounted to 75.0 wt. %.

Synthesis of Anionic Negative Type Photosensitive Coating (X-4)

To 500 g of the produced solution of the half ester (x-9) were added27.0 g of "IRGACURE 907" manufactured by CIBA GEIGY INC. and 3.0 g of"KAYACURE DETX", manufactured by NIPPON KAYAKU CO. LTD., asphotopolymerization initiators. To the resulting mass were added 33.7 gof triethylamine as a neutralizer and the resulting mass was agitatedthoroughly and re-homogenized. Deionized water was added gradually tothe resulting mass and the resulting mixture was agitated vigorouslywith a high-speed mixture to effect dispersion in water to prepare anaqueous solution of an anionic negative type photosensitive coating(X-4) of the anionic electrodeposition type.

SYNTHESIS EXAMPLE 5 Synthesis of Solution of Half-Ester (X-5)

1,000 g of "NISSEKI POLYBUTADIENE-1000", a trade name of a product byNIPPON PETROCHEMICALS CO. LTD. with a number average molecular weight of1,000, an iodine value of 430 and 1,2-linkages of 65 percent, 554 g ofmaleic anhydride, 10 g of xylene and 3.0 g of trimethyl hydroquinone,were charged into a separable flask of a 3 lit. capacity, fitted with athermometer, an agitator, a reflux cooler and a nitrogen blowing tube,and reacted at 190° C. for five hours under a nitrogen stream.Non-reacted maleic anhydride and xylene were distilled off to producemaleinated polybutadiene maleinate with a total acid value of 400 mgKOH/g.

1,000 g of the aforementioned maleinated polybutadiene, 461.8 g ofdiethylene glycol dimethyl ether, 3.0 g of N,N-dimethyl benzylamine and385.5 g of benzyl alcohol, were charged into a separable flask of a 3lit. capacity fitted with a reflux cooling tube, and dissolveduniformly. The resulting mass was reacted at 120° C. for two hours undera nitrogen stream to produce a solution of a half-ester (X-5). The totalacid value of the produced half ester (X-5) in solution was 109.3 mgKOH/g and the non-volatile content accounted for 75.0 wt. %.

SYNTHESIS EXAMPLE 6 Preparation of colored Coatings (Y-1, Y-2 and Y-3)

A solution of the cationic resin (x-8), a photopolymerization initiatorand pigments were mixed under agitation and dispersed by a laboratorytype three-roll roll mill produced by KODAIRA SEISAKUSHO KK until thepigment reached a particle size of 0.2 μm or less. The particle size wasmeasured using a COULTER counter N4 produced by COULTER INC. To eachresulting dispersion mixture was added acetic acid as a neutralizer andeach of the mixtures was agitated thoroughly for re-homogenization. Eachof the resulting masses was dispersed in water under gradual addition ofdeionized water and under agitation vigorously with a high-speed mixer,to produce each colored coating (Y-1, Y-2 and Y-3) having a solidconcentration of 10 wt. %. The compositions of the aqueous solutions ofthe three-color colored coatings (cationic electrodeposition type) areshown in Table 1, where the numerical figures denote parts by weight.

                  TABLE 1                                                         ______________________________________                                                          Coating                                                                       Y-1   Y-2      Y-3                                                            Color                                                                         Red   Green    Blue                                         ______________________________________                                        Cationic resin (x-8) solution                                                                     213.3   213.3    213.3                                    IRGACURE 907 (*)    11.5    11.5     11.5                                     KAYACURE DETX (**)   1.3     1.3      1.3                                     Acetic acid (Neutralizer)                                                                         19.8    19.8     19.8                                     Phthalocyanine Blue (***)                                                                         --      --       20                                       Phthalocyanine Green (****)                                                                       --      20       --                                       Azo Metal Salt Red Pigment (*****)                                                                20      --       --                                       ______________________________________                                         (*) "IRGACURE 907" mfd. by CIBA GEIGY INC.                                    (**) "KAYACURE DETX" mfd. by NIPPON KAYAKU CO., LTD.                          (***) Phthalocyanine Blue "SR150C" (mfd. by SANYO SHIKISO KK)                 (****) Phthalocyanine Green "SAX" (mfd. by SANYO SHIKISO KK)                  (*****) "PIGMENT RED 4BS" (mfd. by SANYO SHIKISO KK)                     

SYNTHESIS EXAMPLE 7 Preparation of Colored Coatings (Y-4, Y-5 and Y-6)

The solution of the half-ester (X-5) and a pigment were mixed underagitation and dispersed by a laboratory type three-roll roll mill,manufactured by KODAIRA SEISAKUSHO KK, until the pigment particle sizeof 0.2 μm or less was reached. The particle size was measured using aCOULTER counter No. 4 manufactured by COULTER INC. To each resultingdispersion mixture was added triethylamine as a neutralizer and theresulting mixture was agitated sufficiently and re-homogenized.Deionized water was added gradually and each resulting mass was agitatedvigorously by a high-speed mixer to effect dispersion in water toprepare each of colored coatings (Y-4, Y-5 and Y-6) having a solidconcentration of 10 wt. %. The compositions of the aqueous solutions ofthe three-color colored coatings of the anionic electrodeposition typeare shown in Table 2. The numerical values in Table 2 represent parts byweight.

                  TABLE 3                                                         ______________________________________                                                          Coating                                                                       Y-4   Y-5      Y-6                                                            Color                                                                         Red   Green    Blue                                         ______________________________________                                        Half Ester (X-5) Solution                                                                         213.3   213.3    213.3                                    Triethylamine (Neutralizer)                                                                        21.0    21.0     21.0                                    Phthalocyanine Blue (*)                                                                           --      --       20                                       Phthalocyanine Green (**)                                                                         --      20       --                                       Azo Metal Salt Red Pigment (***)                                                                  20      --       --                                       ______________________________________                                         (*) "SR150C" manufactured by SANYO SHIKISO KK                                 (**) "SAX" manufactured by SANYO SHIKISO KK                                   (***) "Pigment Red 4BS" manufactured by SANYO SHIKISO                    

SYNTHESIS EXAMPLE 8 Preparation of Black-Hued Coating (Y-7)

To 500 g of a solution of the cationic resin (x-8) were added 27.0 g of"IRGACURE 907" produced by CIBA GEIGY INC. as a photopolymerizationinitiator, 3.0 g of "KAYACURE DETX" produced by NIPPON KAYAKU CO., LTD.,and 37.5 g of "CARBON BLACK #5B", produced by MITSUBISHI KASEICORPORATION, under agitation and the resulting mass was dispersed by alaboratory three-roll roll mill produced by KODAIRA SEISAKUSHO KK, untilthe carbon black reached a particle size of 0.2 μm or less. The particlesize was measured using a COULTER counter N4 produced by a COULTER INC.To the resulting dispersion mixture were added 16.7 g of acetic acid asa neutralizer and agitated thoroughly for re-homogenization. Theresulting mass was dispersed in water under gradual addition ofdeionized water and agitated vigorously by a high-speed mixer to producea black-hued coating material (Y-7) (cationic electrodeposition type)having a solid concentration of 15 wt. %.

SYNTHESIS EXAMPLE 9 Preparation of Black-Hued Coating (Y-8)

To 500 g of a solution of the half ester (x-9) were added, underagitation, 27.0 g of "IRGACURE 907" produced by CIBA GEIGY INC. as aphotopolymerization initiator, 3.0 g of KAYACURE DETX, produced byNIPPON KAYAKU CO., LTD. and 37.5 g of "CARBON BLACK #5B" for mixing andthe resulting mixture was dispersed by a laboratory three-roll rollmill, produced by KODAIRA SEISAKUSHO KK until the carbon black reachedthe particle size of 0.2 μm or less. The particle size was measuredusing a COULTER counter N4 produced by COULTER INC. To the resultingdispersion mixture were added 33.7 g of triethylamine as a neutralizerand agitated thoroughly for re-homogenization. The resulting mass wasagitated vigorously by a high-speed mixer under gradual addition ofdeionized water for dispersion in water to produce a colored coating(Y-8) having a solid concentration of 15 wt. %.

SYNTHESIS EXAMPLE 10 Synthesis of UV Curable Type Pressure SensitiveAdhesive

A mixture of 80 parts by weight of 2-ethylhexyl acrylate, 5 parts byweight of tetrahydrofurfuryl acrylate, 15 parts by weight of acrylicacid, 4 parts by weight of α, α'-azobisisobutyronitrile and 200 parts byweight of toluene was reacted at 80° C. for eight hours under agitationin a N₂ flow to produce a copolymer solution. The solution was raised toa temperature of 100° C., and a mixed solution composed of 5 parts byweight of glycidyl methacrylate, 0.5 part by weight of triethyl benzylammonium chloride and 0.1 part by weight of methoquinone was addeddropwise over 30 minutes. The reaction was carried out for 20 hours atthe same temperature to produce a prepolymer. 5 parts by weight of"IRGACURE 907" produced by CIBA GEIGY INC. as a photopolymerizationinitiator were added to the produced prepolymer to produce a UV curabletype pressure sensitive adhesive.

EXAMPLE 1

With the use, as a cathode, of a substrate obtained by forming apolyimide film 0.8 μm in thickness by spin coating on a glass plate 1 mmin thickness and having a silicone resin layer (50 nm in thickness) onits surface, and by depositing an indium-tim oxide (ITO) film bysputtering thereon to have a thickness of 200 nm, referred tohereinafter as a master plate 1, and with the use, as an anode, of astainless steel beaker, containing an aqueous solution of a cationicpositive type photosensitive coating (X-1), electrodeposition wascarried out for 60 seconds with a dc voltage of 40 V and a temperatureof 25° C. After washing the master plate 1 with ion-exchanged water, themaster plate 1 was dried at 80° C. for five minutes and cooled to form anon-tacky uniform coating with a film thickness of 2 μm.

A mask shown in FIG. 2 was intimately contacted with the coating filmand irradiated with UV rays of 500 mJ/cm² using a UV exposure devicehaving a high pressure mercury lamp, manufactured by ORC MANUFACTURINGCO., LTD. under trade name of JL-3300. The mask was then displaced onthe coating film transversely to a position shown in FIG. 3 andintimately contacted with the coating film. The mask was then irradiatedwith UV rays of 50 mJ/cm². The mask was further displaced on the coatingfilm to a position shown in FIG. 4 and intimately contacted with thecoating film followed by irradiation with UV rays of 100 mJ/cm².

On development with a 0.3 wt. % aqueous solution of sodium metasilicate,only the portions 2 of the cationic positive type photosensitive coatingfilm irradiated with the largest irradiation amounts were selectivelyremoved to expose the ITO layer. After washing with water and drying,electrodeposition was carried out by applying a d.c. voltage of 25 V wasapplied across the master plate 1 as a cathode and a stainless steelbeaker containing a colored coating Y-1 as an anode. After washing themaster plate 1 with ion-exchanged water, followed by drying at 80° C.for five minutes, a red-hued colored layer, 2 μm in thickness, which wasnot tacky at ambient temperature, was produced on the master plateportions freed of the coating film.

After development with a 1.3 wt. % aqueous solution of sodiummetasilicate, no changes were noticed in the red-hued colored layer,while only the positive type photosensitive coating film in registerwith the portions 4 irradiated with the second largest irradiationamounts were selectively removed. After washing with water and drying,the colored coating Y-2 was electrodeposited for three minutes underconditions of a d.c. voltage of 25 V and a temperature of 25° C., in thesame manner as when electrodepositing the colored coating Y-1, and theresulting substrate was washed with ion-exchanged water. It was foundthat there were no changes in the previously formed red-hued coloredlayer, and a greed-hued colored layer was formed on the master plateportions freed of the coating film. After drying at 80° C. for fiveminutes and development with a 3.0 wt. % aqueous solution of sodiummetasilicate, it was found that no changes were produced in the red-huedor green-hued colored layers, and only the positive type photosensitivecoating film portions in register with the portions 3 irradiated withthe third largest irradiation amount were selectively removed. Afterwashing with water and drying, a colored coating Y-3 waselectrodeposited for three minutes in the same manner as forelectrodepositing the colored coating Y-1, under conditions of a d.c.voltage of 25 V and a temperature of 25° C. After washing the masterplate 1 with ion-exchanged water, it was found that no changes wereproduced in the previously formed red-hued or green-hued colored layers,and a blue-hued colored layer was formed on the master plate portionsfreed of the coating film. After further drying at 80° C. for fiveminutes and development with a 3.0 wt. % aqueous solution of sodiumhydroxide, it was found that no changes were produced in the coloredlayers, and the residual cationic positive type photosensitive coating,that is the photosensitive coating film portions in register with theportions 1 irradiated with the smallest irradiation amount, wereselectively removed. After drying at 100° C. for 20 minutes,electroplating was carried out for three minutes, at a current densityof 0.1 A/cm², in a nickel plating bath of 45° C., using the exposed ITOlayer as a cathode. After washing with water and drying, a master plate1 having a non-transmitting or light-intercepting nickel plated layerand the colored layers was produced.

An UV-curable type pressure sensitive adhesive, prepared in SynthesisExample 10, was spin-coated on a transparent glass transcriptionsubstrate to have a thickness of 0.5 μm. After irradiation with UV raysof 100 mJ/cm², the master plate 1 was pressure contacted with thetranscription substrate, using a rubber roll so that the surface of thecolored layers of the master plate 1 was contacted with the adhesive,for transcribing the polyimide film, the ITO layer, the Ni plated layerand the colored layers onto the transparent glass transcriptionsubstrate. The master plate 1 was then peeled off. For completingcuring, the transcription substrate was baked at 150° C. for 30 minutesto produce a color filter having the colored layers excellent intransparency and homogeneity, the ITO layer (transparent electricallyconductive layer) and the polyimide film.

EXAMPLE 2

With the use as an anode of a substrate, obtained by rubbing apolytetrafluoethylene plate 0.5 mm thickness by a rotating roll method,spin-coating a polyimide film 0.5 μm thickness on the rubbed surface andsputtering an ITO film to have a thickness of 150 nm, referred tohereinafter as a master plate 2, and with the use as a cathode of astainless steel beaker containing an aqueous solution of an anionicpositive type photosensitive coating X-2, electrodeposition was carriedout for two minutes at a d.c. voltage of 45 V and a temperature of 25°C. After washing the master plate 2 with ion-exchanged water, followedby drying at 80° C. for five minutes, a uniform non-tacky coating film,having a film thickness of 2.0 μm, was produced.

A mask shown in FIG. 2 was intimately contacted with the coating filmand irradiated with UV rays of 500 mJ/cm² with the use of a UV exposuredevice manufactured by ORC MANUFACTURING CO., LTD. under the trade nameof JL-3300. The mask was then transversly displaced on the coating filmto a position shown in FIG. 3 and irradiated with UV rays of 50 mJ/cm²as the mask was intimately contacted with the coating film. The mask wasfurther displaced on the coating film to a position shown in FIG. 4followed by irradiation of UV rays of 100 mJ/cm² while being intimatelycontacted with the coating film.

After development with a 0.5 wt. % aqueous solution of sodiummetasilicate, only the anionic positive type photosensitive coating filmportions in register with the portions 2 irradiated with the largestirradiation amount were selectively removed to expose the ITO filmthereat. After washing with water and drying, electrodeposition wascarried out by applying a d.c. voltage of 25 V at 30° C. for threeminutes across the master plate 2 as a cathode and a stainless steelbeaker containing the colored coating Y-1 as an anode. After washing themaster plate 2 with ion-exchanged water and drying at 80° for fiveminutes, a red-hued colored layer, 2 μm film thickness, which was nottacky at ambient temperature, was formed on the master plate portionsfreed of the coating film.

Then, after development with a 1.5 wt. % aqueous solution of sodiummetasilicate, it was found that no changes were produced in the red-huedcolored layer, while only the positive type photosensitive coating filmportions in register with the portions 4 irradiated with the secondlargest irradiation amounts were selectively removed. After washing withwater and drying, a colored coating Y-2 was electrodeposited for threeminutes under conditions of the d.c. voltage of 30 V and a temperatureof 25° C., in the same manner as for electrodeposition of the coloredcoating Y-1. After subsequent washing with ion-exchanged water, it wasfound that no changes were produced in the previously formed red-huedcolored layer 2, and a green-hued colored layer was formed on the masterplate portions freed of the coating film. After drying at 80° C. forfive minutes and development with a 4.0 wt. % aqueous solution of sodiummetasilicate, it was found that no changes were produced in the red-huedand green-hued colored layers and only the positive type photosensitivecoating film portions in register with the portions 3 irradiated withthe third largest irradiation amount were selectively removed. Afterwashing with water and drying, the colored coating Y-3 waselectrodeposited for three minutes at a d.c. voltage of 30 V and atemperature of 25° C. in the same manner as for electrodepositing thecolored coating Y-1. After washing the master plate 2 with ion-exchangedwater, it was found that no changes were produced in the previouslyformed red-hued or green-hued colored layers, and a blue-hued coloredlayer was produced on the master plate portions freed of the coatingfilm.

Then, after drying at 80° C. for five minutes and development with a 7.0wt. % aqueous solution of sodium metasilicate, it was found that nochanges were produced in the colored layers, and only the residualanionic positive type photosensitive coating film, that is thephotosensitive coating film portions in register with the portions 1irradiated with the smallest irradiation amount, were selectivelyremoved. After electrodeposition of the colored coating Y-7 for threeminutes at 30 V at 25° C., in the same manner as for electrodepositingthe colored coating Y-1, and washing with ion-exchanged water, followedby drying at 80° C. for five minutes and subsequently cooling the masterplate 2 having red-hued, green-hued, blue-hued and black-hued coloredlayers was produced.

Then, by placing the surface of the colored layers of the master plate 2in contact with the transparent glass substrate, the colored layers, thetransparent electrically conductive layer and the polyimide layer weretranscribed onto the glass substrate, at a laminator pressure of 2kgf/cm², a roll temperature of 100° C. and a laminator speed of 300mm/min. The master plate 2 was then peeled off. After baking at 160° C.for 20 minutes to complete curing, a color filter having transparent andhomogeneous colored layers and also having an ITO film (transparentelectrically conductive Layer) and a polyimide film was produced.

EXAMPLE 3

With the use as a cathode of a substrate similar to that used in Example2, referred to hereinafter as a master plate 3, and with the use as ananode of a stainless steel beaker containing an aqueous solution of acationic negative type photosensitive coating X-3, electrodeposition wascarried out at a d.c. voltage of 30 V and a temperature of 25° C. Afterwashing the master plate 3 with ion-exchanged water, followed by dryingat 80° C. for five minutes and subsequent cooling, a non-tacky uniformcoating film having a film thickness of 2 μm was produced.

The mask shown in FIG. 2 was intimately contacted with the coating film,and irradiated with UV rays of 500 mJ/cm², using a UV exposure devicehaving a high-pressure mercury lamp, manufactured by ORC MANUFACTURINGCO., LTD. under the trade name of JL-3300. The mask was then displacedtransversely on the coating film to a position shown in FIG. 3 andirradiated with UV rays of 50 mJ/cm² as the mask was intimatelycontacted with the coating film. The mask was then displaced on thecoating film to a position shown in FIG. 4, and irradiated with UV raysof 100 mJ/cm², as the mask was intimately contacted with the coatingfilm.

Then, after development with a 0.1 wt. % aqueous solution of lacticacid, only the cationic negative type photosensitive coating filmportions in register with the portions 1 irradiated with the smallestirradiation amount were selectively removed to expose the ITO filmsurface thereat. After washing with water and drying, electroplating wascarried out for 2.5 minutes at a current density of 0.1 A/cm² in acopper plating bath maintained at 45° C., using the master plate 3 as acathode. After washing with water and drying, electrodeposition wascarried out by applying a d.c. voltage of 25 V at 25° C. across themaster plate 3 as an anode and a stainless steel beaker containing acolored coating Y-8 as a cathode. After washing the master plate 3 withion-exchanged water, the master plate 3 was obtained, in which ablack-hued colored layer was formed on the copper plated layer portionsfreed of the coating film.

Then, after development with a 0.5 wt. % aqueous solution of lacticacid, no changes were noticed in the black-hued colored layer, whilstonly the negative type photosensitive coating film portions in registerwith the portions 3 irradiated with the second smallest irradiationamount were selectively removed. After washing with water and drying,the colored coating Y-4 was electrodeposited for three minutes underconditions of a d.c. voltage of 25 V and a temperature of 25° C. Afterwashing with ion-exchanged water, it was found that no changes wereproduced in the previously formed black-hued colored layer, and ared-hued colored layer was formed on the master plate portions freed ofthe coating film. After drying at 80° C. for five minutes anddevelopment with a 3.0 wt. % of lactic acid, it was found that nochanges were produced in the black-hued or red-hued colored layers, andonly the negative type photosensitive coating film portions in registerwith the portions 4 irradiated with the third smallest irradiationamount were selectively removed. After washing with water and drying,the colored coating Y-5 was electrodeposited for three minutes underconditions of a d.c. voltage of 25 V and a temperature of 25° C. in thesame manner as for electrodeposition of the colored coating Y-8. Afterwashing the master plate 3 with ion-exchanged water, it was found thatno changes were produced in the previously formed black-hued or red-huedcolored layers, and a green-hued colored layer was formed in the masterplate portions freed of the coating film.

Then, after drying at 80° C. for five minutes, and development with a7.0 wt. % aqueous solution of lactic acid, no changes were noticed inthe colored layers, and only the residual cationic negative typephotosensitive coating film, that is the photosensitive coating filmportions in register with the portions 2 irradiated with the largestirradiation amount, were selectively removed. After electrodepositionfor three minutes at 25° C. with the d.c. voltage of 25 V, using theexposed ITO surface as an anode and a stainless steel beaker containingthe colored coating Y-6 as a cathode, washing the master plate 3 withion-exchanged water and drying at 80° C. for five minutes, the masterplate 3 in which a blue-hued colored layer having a film thickness of 2μm and not showing tackiness at ambient temperature was produced in themaster plate portions freed of the coating film and which had the copperplated layer, the black-hued colored layer, the red-hued colored layer,the green-hued colored layer and the blue-hued colored layer, wasproduced.

Then, by placing the master plate 3 so that the colored layer surfacethereof was in contact with a transparent glass substrate, the coloredlayers, copper plated layer, the transparent electrically conductivelayer and the polyimide layer were transcribed to the glass substrate ata laminator pressure of 2 kgf/cm², a roll temperature of 100° C. and alaminator speed of 300 mm/min. The master plate 3 was peeled off. Bybaking at 160° C. for 20 minutes to complete the curing, a color filterhaving the polyimide film and the ITO film (transparent electricallyconductive film) on the colored layers and showing excellenttransparency and uniformity, could be obtained.

EXAMPLE 4

By electrodeposition for three minutes under conditions of a d.c.voltage of 25 V and a temperature of 25° C., with the use as an anode ofa master plate 4 similar to the substrate of Example 2, and with the useas a cathode of a stainless steel beaker containing an aqueous solutionof an anionic negative type photosensitive coating X-4, followed bywashing of the master plate 4 with ion-exchange water, drying at 80° C.for five minutes and cooling, a non-tacky uniform coating film with afilm thickness of 1.8 μm was produced.

The mask shown in FIG. 2 was intimately contacted with the coating filmand irradiated with UV rays of 600 mJ/cm², using a UV exposure devicehaving a high-pressure mercury lamp, manufactured by ORC MANUFACTURINGCO., LTD. under the trade name of JL-3300. The mask was then displacedtransversely on the coating film to a position shown in FIG. 3, andirradiated with UV rays of 50 mJ/cm², as the mask was intimatelycontacted with the coating film. The mask was then displaced on thecoating film to a position shown in FIG. 4, and irradiated with UV raysof 100 mJ/cm², as the mask was intimately contacted with the coatingfilm.

Then, after development with a 0.1 wt. % aqueous solution of sodiumcarbonate, only the anionic negative type photosensitive coating filmportions in register with the portions 1 irradiated with the smallestirradiation amount were selectively removed to expose the ITO filmsurface. After washing with water and drying followed byelectrodeposition at 25° C. for three minutes at a d.c. voltage of 30 V,with the use as a cathode of the master plate 4 and with the use as ananode of a stainless steel beaker containing a colored coating Y-7,followed by washing the master plate 4 with ion-exchanged water anddrying at 80° C. for five minutes, a black-hued colored layer was formedon the master plate portions freed of the coating film.

Then, after development with a 0.75 wt. % aqueous solution of sodiumcarbonate, no changes were noticed in the black-hued colored layer, andonly the negative type photosensitive coating film portions in registerwith the portions 3 irradiated with the second smallest irradiationamount were selectively removed. After washing with water and drying,the colored coating Y-2 was electrodeposited for three minutes under theconditions of a d.c. voltage of 30 V and a temperature of 25° C., in thesame manner as for electrodeposition of the colored coating Y-7. Afterwashing with ion-exchanged water, no changes were noticed in thepreviously formed black-hued layer, and a green-hued colored layer wasformed on the portions freed of the coating film. After drying at 80° C.for five minutes and development with a 5.0 wt. % aqueous solution ofsodium metasilicate, no changes were noticed in the black-hued orgreen-hued colored layers, and only the negative type photosensitivecoating film portions in register with the portions 4 irradiated withthe third smallest irradiation amount were selectively removed. Afterwashing with water and drying, the colored coating Y-3 waselectrodeposited for three minutes under conditions of a d.c. voltage of30 V and the temperature of 25° C., in the same manner as forelectrodeposition of the colored coating Y-7. After washing the masterplate 4 with ion-exchange water, it was found that no changes wereproduced in the previously formed black-hued or green-hued coloredlayers, and a blue-hued colored layer was formed in the portions freedof the coating film.

Then, after drying at 80° C. for five minutes and development with a 9.0wt. % aqueous solution of sodium metasilicate, it was found that nochanges were produced in the colored layers and the residual anionicnegative type photosensitive coating, that is the photosensitive coatingfilm portions in register with the portions 2 irradiated with thelargest irradiation amount, were selectively removed. After washing withwater and drying, the colored coating Y-1 was electrodeposited for threeminutes at 25° C. at a d.c. voltage of 30 V in the same manner as forelectrodepositing the colored coating Y-7. After washing the masterplate 4 with ion-exchanged water, the master plate 4 in which a red-huedcolored layer was formed in the portions freed of the coating film andwhich had the black-hued, green-hued and red-hued colored layers, wasproduced.

Then, by placing the master plate 4 so that the surface of its coloredlayers is contacted with a transparent glass substrate, on which the UVcurable pressure sensitive adhesive obtained in Synthesis Example 10 wasspin coated to have a thickness of 0.1 μm, the colored layers, thetransparent electrically conductive layer and the polyimide layer weretranscribed onto the glass substrate, using a rubber roll, and wereirradiated with UV rays of 200 mJ/cm². The master plate 4 was peeledoff. After baking at 150° C. for 30 minutes to complete the curing, acolor filter having the ITO film (transparent electrically conductivefilm) and the polyimide film on the upper surface of the colored layersand having excellent transparency and uniformity was produced.

Although the present invention has been described with reference to thepreferred examples, it should be understood that various modificationsand variations can be easily made by those skilled in the art withoutdeparting from the spirit of the invention. Accordingly, the foregoingdisclosure should be interpreted as illustrative only and is not to beinterpreted in a limiting sense. The present invention is limited onlyby the scope of the following claims.

What is claimed is:
 1. A method for producing a color filter comprisingthe steps of:(A) forming a photosensitive coating film on a transparentelectrically conductive layer provided on an outermost surface of asubstrate having an alignment film, and exposing said photosensitivecoating film to light in a first irradiation amount through a maskhaving a predetermined pattern of a certain light transmittance, and atleast once displacing said mask to another position on saidphotosensitive coating film so as to not overlap with previous positionand exposing said photosensitive coating film to light in a secondirradiation amount different from said first irradiation amount throughsaid mask, (B) developing and removing a photosensitive coating filmportion exposed to light in one of smallest and largest irradiationamounts for exposing the transparent electrically conductive layer andelectrodepositing a colored coating on the exposed electricallyconductive layer for forming a colored layer thereon, operation ofdeveloping and removing the photosensitive coating film andelectrodepositing the colored coating being repeated in sequence ofdifference in irradiation amounts to form different colored layers,respectively; and (C) transcribing said colored layers, said transparentelectrically conductive layer and said alignment film onto anothersubstrate.
 2. The method as claimed in claim 1 wherein said substratehaving the transparent electrically conductive layer comprises a releaselayer between said alignment film and a surface of said substrate. 3.The method as claimed in claim 1 wherein said alignment film is made ofa material selected from the group consisting of silica, polyimide,polyphenylene sulfide, epoxy resin, acrylic resin and mixtures thereof.4. The method as claimed in claim 1 wherein said alignment film isproduced by a method selected from the group consisting of an obliquevacuum deposition method, a grating method, a rubbing method and aplasma polymerization method.
 5. The method as claimed in claim 1wherein said photosensitive coating film is formed by a method selectedfrom the group consisting of electrodeposition, spraying, dip coating,roll coating, screen printing and spin coating.
 6. The method as claimedin claim 1 wherein said photosensitive coating film is formed of anegative type photosensitive coating containing a negative typephotosensitive coating resin exhibiting coating film forming capabilityand photosensitivity, a photopolymerization initiator and a solventselected from the group consisting of an organic solvent and water, andwherein said operation is repeated in sequence of increasing irradiationamounts.
 7. The method as claimed in claim 6 wherein said negative typephotosensitive coating resin has a molecular weight ranging between 500and 10,000.
 8. The method as claimed in claim 6 wherein said negativetype photosensitive coating resin is a prepolymer selected from thegroup consisting of epoxy (meth)acrylate, urethane (meth)acrylate,polyester (meth)acrylate and mixtures thereof.
 9. The method as claimedin claim 6 wherein said negative type photosensitive coating resin is anonium group-containing cationic resin prepared by introducing an oniumgroup and a photosensitive group into a main resin and processing withan acidic material, said main resin being selected from the groupconsisting of acrylic resin, polyester resin, maleinated oil resin,epoxy resin, urethane resin, polybutadiene resin, polyamide resin andmixtures thereof, said onium group being selected from the groupconsisting of an amino group, an ammonium group, a sulfonium group andmixtures thereof, said photosensitive group being selected from thegroup consisting of an acryloyl group, a methacryloyl group, a cinnamoylgroup and mixtures thereof, and said acidic material being selected fromthe group consisting of formic acid, acetic acid, propionic acid, lacticacid and mixtures thereof.
 10. The method as claimed in claim 6 whereinsaid negative type photosensitive coating resin is a carboxyl groupcontaining anionic resin obtained by introducing a carboxyl group and aphotosensitive group into a main resin and processing with a basicsubstance, said main resin being selected from the group consisting ofacrylic resin, polyester resin, maleinated oil resin, polybutadieneresin, epoxy resin, urethane resin, polyamide resin and mixturesthereof, said photosensitive group being selected from the groupconsisting of an acryloyl group, a methacryloyl group, a cinnamoyl groupand mixtures thereof, said basic substance being selected from the groupconsisting of triethylamine, diethylamine, dimethylethanol amine,ammonia and mixtures thereof.
 11. The method as claimed in claim 6wherein said photopolymerization initiator is selected from the groupconsisting of benzoins, benzoin ethers, benzylalkyl ketals, benzophenonederivatives, anthraquinone derivatives, thioxanthone derivatives andmixtures thereof.
 12. The method as claimed in claim 6 wherein an addedamount of said photopolymerization initiator is 0.05 to 30 parts byweight to 100 parts by weight of said negative type photosensitivecoating resin.
 13. The method as claimed in claim 6 wherein said organicsolvent is selected from the group consisting of ethyleneglycolmonobutyl ether, ethyleleglycol monohexyl ether, ethyleneglycolmonophenyl ether, propyleneglycol monomethyl ether, propylneglycolmonophenyl ether, diethyleneglycol dimethyl ether, triethyleneglycoldimethyl ether, acetone, methylethyl ketone, methylisobutyl ketone,cyclohexanone, isophorone, dibutyl ether, dioxane, tetrahydrofuran,methoxy butanol, diacetone alcohol, butanol, isopropanol, toluene,xylene, hexane, ethyl acetate, butyl acetate, 2-methoxyethyl acetate,2-methoxypropyl acetate, ethyl benzoate, dimethyl formamide,N,N-dimethyl acetoamide, dimethyl sulfoxide and mixtures thereof. 14.The method as claimed in claim 6 wherein said negative typephotosensitive coating contains a colorant selected from the groupconsisting of dyes, pigments and mixtures thereof.
 15. The method asclaimed in claim 14 wherein said dye is selected from the groupconsisting of azo dyes, anthraquinone dyes, benzodifuranone dyes,condensed methine dyes and mixtures thereof.
 16. The method as claimedin claim 14 wherein said pigment is selected from the group consistingof azo lake organic pigments, quinacridone organic pigments,phthalocyanine organic pigments, isoindolinone organic pigments,anthraquinone organic pigments, thioindigo organic pigments, chromeyellow, iron oxide, chrome vermilion, chome green, ultramarine, prussianblue, cobalt blue, cobalt green, emerald green, titanium white, carbonblack and mixtures thereof.
 17. The method as claimed in claim 14wherein said colorant is used in an amount of 3 to 70 wt. % based on atotal amount of the negative type photosensitive coating.
 18. The methodas claimed in claim 1 wherein said photosensitive coating film is formedof a positive type photosensitive coating containing a positive typephotosensitive coating resin having coating film forming capability andphotosensitivity and a solvent selected from the group consisting of anorganic solvent and water, and wherein said operation is repeated insequence of decreasing irradiation amounts.
 19. The method as claimed inclaim 18 wherein said positive type photosensitive coating resin is aquinone diazido group-containing cationic resin obtained by introducingan onium group and a hydroxyl group into a main resin, adding a quinonediazido sulfonic acid compound by esterification reaction and processingwith an acidic material, said main resin being selected from the groupconsisting of acrylic resin, polyester resin, maleinated oil resin,epoxy resin, urethane resin, polybutadiene resin, polyamide resin andmixtures thereof, said onium group being selected from the groupconsisting of an amino group, an ammonium group, a sulfonium group andmixtures thereof, and said acidic material being selected from the groupconsisting of formic acid, acetic acid, propionic acid, lactic acid andmixtures thereof.
 20. The method as claimed in claim 18 wherein saidpositive type photosensitive coating resin is a quinone diazidogroup-containing anionic resin obtained by introducing a carboxyl groupand a hydroxyl group into a main resin, adding a quinone diazidosulfonic acid compound by esterification reaction and processing with abasic substance, said main resin being selected from the groupconsisting of acrylic resin, polyester resin, maleinated oil resin,polybutadiene resin, epoxy resin, urethane resin, polyamide resin andmixtures thereof, and said basic substance being selected from the groupconsisting of triethylamine, diethylamine, dimethylethanol amine,ammonia and mixtures thereof.
 21. The method as claimed in claim 18wherein said positive type photosensitive coating resin is a quinonediazido group-containing resin obtained by reacting a resin having filmforming capability and a hydroxyl group-containing compound with aquinone diazido compound, said quinone diazido compound being selectedfrom the group consisting of a quinone diazido sulfonic acidderivative-containing quinone diazido compound and an isocyanategroup-containing quinone azido compound.
 22. The method as claimed inclaim 18 wherein said organic solvent is selected from the groupconsisting of ethyleneglycol monobutyl ether, ethylglycol monohexylether, ethyleneglycol monophenyl ether, propyleneglycol monomethylether, propyleneglycol monophenyl ether, diethyleneglycol dimethylether, triethyleneglycol dimethyl ether, acetone, methylethyl ketone,methylisobutyl ketone, cyclohexanone, isophorone, dibutyl ether,dioxane, tetrahydrofuran, methoxy butanol, diacetone alcohol, butanol,isopropanol, toluene, xylene, hexane, ethyl acetate, butyl acetate,2-methoxyethyl acetate, 2-methoxypropyl acetate, ethyl benzoate,dimethylformamide, N,N-dimethyl acetoamide, dimethyl sulfoxide andmixtures thereof.
 23. The method as claimed in claim 18 wherein saidpositive type photosensitive coating contains a colorant selected fromthe group consisting of dyes, pigments and mixtures thereof.
 24. Themethod as claimed in claim 23 wherein said dye is selected from thegroup consisting of azo dyes, anthraquinone dyes, benzodifuranone dyes,condensed methine dyes and mixtures thereof.
 25. The method as claimedin claim 23 wherein said pigment is selected from the group consistingof azo lake organic pigments, quinacridone organic pigments,phthalocyanine organic pigments, isoindolinone organic pigments,anthraquinone organic pigments, thioindigo organic pigments, chromeyellow, iron oxide, chrome vermilion, chrome green, ultramarine,prussian blue, cobalt blue, cobalt green, emerald green, carbon blackand mixtures thereof.
 26. The method as claimed in claim 23 wherein 3 to70 wt. % of said colorant is contained based on total weight of saidpositive type photosensitive coating.
 27. The method as claimed in claim1 wherein said mask has a light-transmitting portion and a nonlight-transmitting portion.
 28. The method as claimed in claim 27wherein said mask has such a width between said light-transmittingportion and said non light-transmitting portion adjacent to saidlight-transmitting portion that when said mask is displaced, saidlight-transmitting portion is not overlapped with said nonlight-transmitting portion.
 29. The method as claimed in claim 1 whereinsaid photosensitive coating film is developed and removed by adeveloping solution selected from the group consisting of an aqueoussolution containing an acidic material dissolved therein, an aqueoussolution containing a basic material dissolved therein, alcohols, glycolethers, ketones and chlorinated hydrocarbons.
 30. The method as claimedin claim 29 wherein said acidic material is selected from the groupconsisting of formic, acid, acetic acid, propionic acid, lactic acid,hydrochloric acid, phosphoric acid and mixtures thereof.
 31. The methodas claimed in claim 29 wherein said basic material is selected from thegroup consisting of sodium carbonate, sodium hydrogen carbonate, sodiummetasilicate, tetraalkyl ammonium hydroxide, sodium hydroxide, potassiumhydroxide and mixtures thereof.
 32. The method as claimed in claim 1wherein said photosensitive coating film is developed and removed underconditions of a temperature of 10° to 70° C. and a developing time of 5to 600 seconds.
 33. The method as claimed in claim 1 wherein saidcolored coating is obtained by processing a film-forming component and acolorant component with a material selected from the group consisting ofan acidic substance and a basic substance, said film-forming componentbeing selected from the group consisting of cationic resins, anionicresins and photocurable resins, said colorant component being selectedfrom the group consisting of dyes, pigments and mixtures thereof, saidacidic substance being selected from the group consisting of formicacid, acetic acid, propionic acid, lactic acid and mixtures thereof, andsaid basic substance being selected from the group consisting oftriethylamine, diethylamine, diethylethanol amine, ammonia and mixturesthereof.
 34. The method as claimed in claim 33 wherein said cationicresin is obtained by introducing an onium group into a main resin, saidmain resin being selected from the group consisting of acrylic resin,polyester resin, maleinated oil resin, epoxy resin, urethane resin,polybutadiene resin, polyamide resin and mixtures thereof, and saidonium group being selected from the group consisting of an amino group,an ammonium group, a sulfonium group and mixtures thereof.
 35. Themethod as claimed in claim 33 wherein said anionic resin is obtained byintroducing a carboxyl group into a main resin selected from the groupconsisting of acrylic resin, polyester resin, maleinated oil resin,polybutadiene resin, epoxy resin, urethane resin, polyamide resin andmixtures thereof.
 36. The method as claimed in claim 33 wherein saidphotocurable resin contains a functional group selected from the groupconsisting of an acryloyl group, a methacryloyl group, a cinnamoyl groupand mixtures thereof in a molecule thereof.
 37. The method as claimed inclaim 33 wherein said photocurable resin comprises a photopolymerizationinitiator selected from the group consisting of benzoins, benzoinethers, benzylalkyl ketals, benzophenone derivatives, anthraquinonederivatives, thioxanthone derivatives and mixtures thereof.
 38. Themethod as claimed in claim 33 wherein said dye is selected from thegroup consisting of azo dyes, anthraquinone dyes, benzodifuranone dyes,condensed methine dyes and mixtures thereof.
 39. The method as claimedin claim 33 wherein said pigment is selected from the group consistingof azo lake organic pigments, quinacridone organic pigments,phthalocyanine organic pigments, isoindolinone organic pigments,anthraquinone organic pigments, thioindigo organic pigments, chromeyellow, iron oxide, chrome vermilion, chrome green, ultramarine,prussian blue, cobalt blue, cobalt green, emerald green, titanium white,carbon black and mixtures thereof.
 40. The method as claimed in claim 1wherein said colored coating is electrodeposited at an electricalvoltage of 5 to 500 V dc for a time interval of 5 to 300 seconds and ata liquid temperature of 10° to 35° C.
 41. The method as claimed in claim1 wherein said another substrate is a transparent substrate selectedfrom the group consisting of glass, polyester, polysulfone, cellulosetriacetate, polycarbonate, polyimide, polystyrene and polymethylpentene.42. The method as claimed in claim 1 wherein a transparent adhesiveselected from the group consisting of a photocurable adhesive, apressure-sensitive adhesive, a hot-melt adhesive, and mixtures thereofis applied on said another substrate before said step (C) is performed.43. The method as claimed in claim 1 further comprising a step ofheating at 50° to 250° C. for 5 minutes to one hour after said step (C)is performed.
 44. The method as claimed in claim 1 further comprising astep of photocuring after said step (C) is performed.
 45. The method asclaimed in claim 1 further comprising, after said step (A) and beforesaid step (C), a step (X) for developing and removing saidphotosensitive coating film exposed to light in at least one irradiationamount to expose the transparent electrically conductive layer followedby selectively forming a metal layer thereon.
 46. The method as claimedin claim 45 further comprising a step (Y) for electrodepositing acolored coating on said metal layer formed in said step (X).
 47. Themethod as claimed in claim 45 wherein a metal of said metal layer isselected from the group consisting of copper, nickel, chromium, silver,gold, an alloy thereof and mixtures thereof.